We developed a scintillator based on a Rb2HfCl6 crystal as a ternary halide crystal with intrinsic luminescence. In the photoluminescence spectra, two emission bands are observed at 383 and 434 nm. The 434 nm emission band for Rb2HfCl6 may be attributed to [HfCl6]2− complex ion or [ZrCl6]2− impurity, since the Rb2HfCl6 contained Zr as impurity at 0.62 mol %. The radioluminescence band is observed at 420 nm and can be attributed to the same origin as the photoluminescence band at 434 nm. The scintillation decay-time constants were 0.84 and 5.4 µs. The light yield was estimated to be 24,100 photons/MeV.

A dinuclear Ru complex, proximal,proximal-[Ru2L­(C8Otpy)2(OH)­(OH2)]3+ (C8Otpy = 4′-octyloxy-2,2’; 6′,2″-terpyridine) (1) with long alkoxyl chains, was synthesized to be immobilized on a carbon paper (CP) electrode via hydrophobic interactions between the long alkoxyl chains and the CP surface. The 1/CP electrode demonstrated efficient electrocatalytic water oxidation with a low overpotential (ηonset) of 0.26 V (based on the onset potential for water oxidation) in an aqueous medium at pH 7.0, which is compared advantageously with those of hitherto-reported molecular anodes for water oxidation. The active species of RuIIIRuIII(μ-OO) with a μ-OO bridge was involved in water oxidation at 0.95 V versus Ag/AgCl. As the applied potential increased to 1.40 V, water oxidation was promoted by participation of the more active species of RuIIIRuIV(μ-OO), and very durable electrocatalysis was gained for more than 35 h without elution of 1 into the electrolyte solution. The introduced long alkoxyl chains act as a dual role of the linker of 1 on the CP surface and decrease the η value. Theoretical investigation provides insights into the O–O bond formation mechanism and the activity difference between RuIIIRuIII(μ-OO) and RuIIIRuIV(μ-OO) for electrocatalytic water oxidation.

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This research clarified the transition mechanism of melt depth in Ti powder bed during Laser Powder Bed Fusion process using in-situ X-ray and thermal imaging. A fiber laser beam of 150 W was irradiated on a powder bed at a scan speed of 15 mm/s for 3.5 s in a vacuum chamber. The obtained X-ray images showed a keyhole depth Ld increased immediately after laser irradiation, gradually decreased, and became constant. It also showed a keyhole width Lw increased immediately after laser irradiation and decreased afterward, after that, Lw increased again, and became constant. Furthermore, thermal images that measured the temperature on the powder bed showed the high temperature width Lh gradually increased and become constant. The model of the driving force which pushed the molten droplet was examined by analyzing the volume and scattering speed of the molten droplet. The model indicated the recoil pressure caused by the vaporization of powder metal was a driving force for the molten droplet scattering. The transition mechanism of keyhole depth was considered as follows. The increase of Ld at the beginning is due to the increase of the recoil pressure PT. This is because the decrease of Lw and large quantity of vaporization. Next, the decrease of Ld is due to the decrease in PT. This is because the increase of Lw and decrease of quantity of vaporization. At last, the transition to the constant Ld is caused by stabilization of Lw and Lh followed by stabilization of PT.